Otherwise it's possible that certain buildtime dependencies, that won't
be linked against, will block a build.

See Homebrew/homebrew#23115.

Copy these files/folders to a .bottle directory under the Cellar for installation
elsewhere at pouring time.

Temporarily disable HOMEBREW_GIT_ETC methods until fixed.

This method allows copying a file to a new location by performing a
substitution on the pathname.

If an etc file exists on installation instead of overwriting it (or
requiring all the manual checks in formula) simply copy it with the
extension `.default` appended.

Fixes Homebrew/homebrew#23115.

This reverts commit 5e26584736b310c365d4b9cce99d0dced9a2d309.

Fixes Homebrew/homebrew#23111.

Fixes Homebrew/homebrew#23089.

A nil stdlib value represents non-C++ code.

After a formula is built, scan all mach-o files for dynamic links
to see if any of them point to a C++ stdlib (libc++ or libstdc++).
If one of them is linked, record that information in the formula's tab.

This replaces the old behaviour where all files were assumed to be C++
code, and stdlibs were always tracked regardless of whether they were
actually linked against.

This also modifies the way that tabs are written - now tabs are written
with the stdlib field null, and values are only written if an stdlib
is detected.

Closes Homebrew/homebrew#23079.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Comparing two objects should not raise an exception, even if they have
different types.

The semantics of #== are now the same as #eql?, so make one an alias.